Choose a chicken with skin that is not torn, and allow it to come to room temperature (if chilled). Chop off the feet and parson's nose (tail) if desired. Wash the skin and body cavity thoroughly. Drain and pat dry with paper towels. Mix salt and pepper together, and rub the inside and all over the skin. Tuck the feet (if left intact) into the cavity, and twist the wings to secure them on the back. Make a 3-inch loop with twine and tie around the neck. Make sure the loop is strong enough to lift the chicken. Set aside.
Wash old ginger and cut into slices. Wash garlic cloves and smash lightly. Roughly chop spring onions into 1-inch lengths.
In a deep stock pot, heat up 2 tbsp oil over medium heat. When hot, fry ginger slices and garlic cloves until fragrant. Add sugar, and continue to fry until sugar melts. Add the chopped spring onions, cinnamon bark, star anise, and fry for a few seconds more.
Pour in the light and dark soy sauces, Chinese rose wine (or Shaoxing wine) and enough water to submerge the chicken. Turn up the heat, and bring to a boil. At this point, before putting in the chicken, do a taste test. If you would like the sauce a little more salty, add the remaining 1 tsp salt (less or more, to your taste), or if you like it a little sweeter, add more sugar to taste. When boiling, lower chicken in, chest side facing down, into the sauce. Allow the sauce to return to a steady simmer, and lift the chicken out.
Turn up the heat and when the sauce is boiling again, lower the chicken in for the second time. When the sauce is simmering again, lift the chicken out. Bring the sauce back to a boil, then lower in the chicken for the third time and leave it in the pot.
When the sauce returns to a steady simmer, turn off the heat. Cover the pot with its lid, and let chicken steep for an hour to an hour 15 minutes, or until just cooked. You can use a meat thermometer to check if chicken is cooked through. Stab it into the thickest part of the thigh (but not touching the bone) and if the temperature reaches at least 75 deg C (165 deg F), it is cooked.
Lift out the chicken and hang it to drip dry (have a drip pan ready to collect the juices). Strain the sauce, set aside some for serving, and store the rest for future use. When the chicken has cooled, brush some oil on the skin. Then chop into pieces and serve with some of the sauce in a bowl, or ladle sauce over the chicken.